Sleep protects and enhances memory in young adults. Specifically, performance changes on a range of tasks are greater following an interval with sleep relative to changes over an interval spent awake. Sleep also enhances encoding of subsequent memories. In young adults, a mid-day nap is sufficient for gaining these performance benefits. Unlike adults, mid-day naps are routine for young children. The age at which children wean from this biphasic sleep pattern is often influenced by parent and school schedules. Whether naps confer a particular benefit to learning and performance of young children is unknown. The research objective of this proposal is to characterize the function of sleep on learning and memory in young children (3-5 yrs) using naps as a model. By probing recall prior to and following mid-day nap or wake intervals, the overarching hypothesis is that mid-day naps benefit existing memories and subsequent learning. In the preschool classroom, children will be trained on a declarative, emotional, or procedural learning task before (Specific Aim 1) or after (Specific Aim 2) a mid-day nap opportunity. In two conditions, children will either be nap-promoted or wake-promoted during this interval. Subsequently, performance will be reassessed that day as well as the following day. The specific hypotheses examined are: a) mid-day naps benefit performance on most tasks learned prior to sleep; b) performance on tasks learned after sleep is superior to performance for tasks learned after wake, and; c) the benefit of sleep remains even after overnight sleep, when differences in sleep pressure and mood are equated. This work is innovative in that it presents a novel application of an accepted theoretical construct. Moreover, these results are expected to shift the current lax practices regarding naps in preschools to a practice of nap-promotion and better regard for the length of the nap opportunity. The translational significance may be seen in new policies regarding in-class nap opportunities and pediatric nap guidelines for preschool children. The theoretical significance is that these outcomes will drive an entirely new research dimension for educational sciences (sleep as a novel target to enhance learning) and spur further developmental studies on the influence and underpinnings of sleep-dependent cognitive and neural processes.